I was born in Rio de Janeiro but went to live in Brasília when I was about 12 years old. Brasília is a city with the shape of an airplane and the wings are the residencial áreas. The wings are divided in small neighbohoods called quadras that have 250 meters per 250 meters and sometimes there is an empty space called "entrequadra" with the same measurements (250 m X 250m) When I've first went to live in Brasília I went to quadra 308 north and made all my friends there, years later I've moved with my family to quadra 106 north. Since my friends were still almost all in 308, I use to walk two quadras and one entrequadra often to see them. One night, past 11 p.m. I was going home and crossed the entrequadra between 308 north and 307 north, that was completed out of light by that time, when a "shadow" with the shape of a dog passed by me. The first thing that came to my mind was "someone is walking a german shepherd out of the leash" so I look back...and saw no one, I was alone at the entrequadra... then I though "that was a stray dog" but, when I looked ahead I saw...absolutely nothing! Thinking that a stray dog simply went away I continued walking ahead then, out of nowhere, the thing passed right beside me and looked in my direction! It seemed like a complete dark (black) shadow, except that was tridimensional, with the shape and size of a big german shepherd and, as it passed by me it disappeared again!!! It did not attack me or made any sound, it was completely silent and on other times I've walked at night I felt like someone or something was watching me. There is a catholic church at that entrequadra and although there's no cemetery there, many people believe that this kind of place attracts supernatural things. Years after I've saw that whatever it may be the government installed a light post at the quadra and I've never ever felt watched or saw anything there when crossing that entrequadra at night.